A study of the role of adipose tissue lipolysis and glycerol release in the control of gluconeogenesis will be undertaken in obese subjects before and after weight reduction and in non-obese volunteers during weight maintenance. The effect of carbohydrate intake and body weight will be studied in relation to the metabolism of adipose tissue, glycerol metabolism, serum lipolytic factors as well as plasma and muscle amino acids. The endocrine controls of lipolysis and energy metabolism will be studied by the measurement of plasma levels of thyroid hormones, in particular T3 and rT3, and levels of adrenocorticotrophic hormone, on various intakes of carbohydrates both before and after weight reduction. The effects of jejuno-ileal shunting as a technique for the treatment of human obesity will be studied in terms of the mechanism of weight loss, effects on cholecystokinin levels and the behavioral consequences of weight reduction by this method. BIBLIOGRAPHIC REFERENCES: Hirsch, Jules and Bruce Batchelor 1976. Adipose tissue cellularity in human obesity, p. 229-311. In Margaret Albrink, Clinics in Endocrinology and Metabolism. W.B. Saunders, London. Hirsch, Jules. The adipose cell hypothesis. N. Engl. J. Med. 295, 7, 389, 1976.